Mahatma's look has a purifying effect. The effect depends on the grades of men coming in contact with Mahatma.

Devotee:  It is said that one look of a Mahatma is enough; that  idols, pilgrimages, etc. are not so effective. I have been here for three months, but I do not know how I have been benefited by the look of Maharshi.

Ramana Maharishi:  The look has a purifying effect. Purification cannot be visualised. Just as a piece of coal takes long to be ignited, a piece of charcoal takes a short time, and a mass of gunpowder is instantaneously ignited, so it is with grades of men coming in contact with Mahatmas.